The Ki-45 Kai-Hei, otherwise designated as Type 2 Two-Seat Fighter, Improved Model C (Hei/丙) (二式複座戦闘機 丙型), was the third production variant of the Ki-45 series. After the relatively poor performance of the previous Ki-45 Kai-Otsu, the 37 mm cannon was replaced back to a 20 mm, while the nose-mounted armament of two 12.7 mm machine guns was replaced by a single Ho-203 37 mm drum-fed autocannon. This variant also solidified the role of the Ki-45 as an interceptor, offering heavy armament and the ability to climb to bomber altitudes to attack them.

It was introduced in Update 1.31. The Ki-45 Kai-Hei is the strongest and most deadly version of the Ki-45 series, delivering a powerful forward burst of 20 mm and 37 mm shells. Playing closer to the Ki-45 Kai-Kō again, as it also features autocannons, though the nose-mounted 37 mm requires trigger discipline since the shells deplete rapidly if the trigger is held down.